(1) Field of the Invention
The present invention relates to a polyphenylene sulfide (hereinafter referred to as "PPS") composition having excellent impact characteristics, melt flowability and flexibility, and a shaped article made therefrom.
(2) Description of the Related Art
As the polyphenylene sulfide resin having improved impact characteristics, there can be mentioned a composition prepared by incorporating into PPS an appropriate amount of an epoxy group-containing .alpha.-olefinic copolymer comprising an .alpha.-olefin and a glycidyl ester of an .alpha., .beta.-unsaturated acid, as proposed in Japanese Unexamined Patent Publication No. 58-154757, and a composition prepared by incorporating an appropriate amount of an .alpha.-olefinic copolymer comprising an .alpha.-olefin and a glycidyl ester of an .alpha., .beta.-unsaturated acid into a polyphenylene sulfide which has been subjected to a specific treatment, as disclosed in Japanese Unexamined Patent Publication No. 62-153343, Japanese Unexamined Patent Publication No. 62-153344 and Japanese Unexamined Patent Publication No. 62-153345.
Compositions prepared by incorporating various elastomers into PPS are disclosed in Japanese Unexamined Patent Publication No. 60-120753, Japanese Unexamined Patent Publication No. 59-113055, Japanese Unexamined Patent Publication No. 58-27740, Japanese Unexamined Patent Publication No. 56-118456 and Japanese Unexamined Patent Publication No. 56-118449.
Among the foregoing known compositions, none of the compositions comprising elastomers provides a satisfactory improvement of the impact characteristics. As is well-known, the molecule chain of polyphenylene sulfide is relatively inactive, and therefore, if any ordinary elastomer is merely incorporated in polyphenylene sulfide, since the affinity of the elastomer with polyphenylene sulfide is poor, satisfactory impact characteristics cannot be obtained.
In the composition prepared by incorporating an olefinic copolymer comprising an .alpha.-olefin and a glycidyl ester of an .alpha., .beta.-unsaturated acid into polyphenylene sulfide, the impact characteristics are improved, and where this olefinic copolymer is incorporated in polyphenylene sulfide which has been subjected to a specific deionizing treatment, the impact characteristics are remarkably improved. Nevertheless, when this olefinic copolymer comprising an .alpha.-olefin and a glycidyl ester of an .alpha.,.beta.-unsaturated acid is incorporated, the melt viscosity of PPS rises, and a serious problem arises of a reduction of the moldability inherently possessed by PPS, and a poor flexibility of the composition.